Apparatus and method for repeated, automatic metering of precisely metered quantities of a powdered detergent into water-carrying cleaning machines, in particular household and household washing machines

ABSTRACT

An apparatus and a method for repeated, automatic metering of precisely metered quantities of a powdered detergent into water-carrying cleaning machines, in particular household dishwashers and household washing machines, include a detergent holder and a metering and dispensing device having a movable metering device with at least one metering receptacle. The interior of the detergent holder and a guide of the metering and dispensing device are acted upon continuously by a stream of compressed air. Therefore, clumping of the highly hygroscopic powdered detergent and an expensive, complex apparatus, which requires a high drive torque and a high air pressure, are avoided. The metering device has only one metering receptacle. The metering and dispensing device has two chambers communicating with one another. The detergent fed into the first chamber is fed gradually, during the motion of the metering device, into the second chamber, which has an opening toward the treatment vessel. The treatment vessel-side opening of the second chamber is closed by a lid connected to the metering device. The lid, in the dispensing position of the metering and dispensing device, uncovers a discharge opening, from which the metered detergent is fed gradually to the treatment vessel. Sealing elements which surround the treatment vessel-side opening of the second chamber are provided, which cooperate with the lid.

This is a division of application Ser. No. 08/580,435 filed on Dec. 27,1995, and now U.S. Pat. No. 5,694,794.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an apparatus and a method for repeated,automatic metering of precisely metered quantities of a powdereddetergent into water-carrying cleaning machines, in particular householddishwashers and household washing machines, including a detergent holderand a metering and dispensing device.

There are machines on the market in which the supply of meteredquantities of a detergent takes place automatically and repeatedly foreach cleaning cycle; the goal is optical cleaning action withsimultaneous reduction in the consumption of energy and in environmentalpollution, as well as the avoidance of mistakes in metering thedetergent.

In the known machines, those demands are intended to be met by usinglarge-capacity metering devices with a metering and dispensing device,which are suitable for automatic, repeated dispensing of exact,predetermined quantities of detergent for each cleaning cycle. Thosedevices are aimed at a treatment chamber of the cleaning machinesreferred to at the outset and typically have a rotating part, which hasa plurality of metering chambers, into which the detergent is pouredfrom an outlet opening of the detergent holder and is pumped to a fixeddischarge opening, from which the detergent is then expelled into theinterior of the treatment chamber of the cleaning machine. In some knowndevices, the expulsion of metered detergent takes place by the weight ofthe detergent itself. In other known devices, the metered detergent isexpelled through the use of a flow of water.

However, those known configurations for automatic, repeated delivery ofaccurately metered quantities of detergent require complex devices whichcan only be manufactured industrially at major effort and expense. Ithas been found in practice that those devices do not always functionreliably, since the highly hygroscopic powdered detergent often clumpstogether as a result of the moisture entering from the treatment vesselof the cleaning machine into the detergent holder and/or the meteringand dispensing device through the necessarily present discharge opening.As a result, the function is impeded, and moreover the lumps aredifficult to remove from the detergent holder of the metering device.Clumping of the powdered detergent represents such a major disadvantagethat in the worst case, from swelling of the volume of the detergent fedinto a metering chamber, complete blockage of the metering device canoccur. Moreover, powdered detergents have a pronounced scouring action,and the escape of detergents into guides, bearings and so forth of themetering device. That disadvantage can be effectively overcome only byusing complicated and expensive seals.

In U.S. Pat. No. 3,188,146, it is proposed, in order to overcome theabove disadvantages, that the detergent holder and the metering anddispensing device be acted upon with compressed air in the dispensingposition of the apparatus. That known apparatus is very complex, andbecause of its enormously large structural size it cannot beaccommodated in modern household dishwashers or household washingmachines. Moreover, the known apparatus has numerous openings andconduits for the detergent, which can easily become plugged by thedetergent and can thus cause disruptions of the known apparatus, up tothe point of complete inability to function.

In order to avoid those disadvantages, Published International PatentApplication WO 93/18702 has disclosed an apparatus of the type referredto at the outset, in which the detergent holder and the apparatus areacted upon continuously by compressed air; the air pressure of thecompressed air in the apparatus is higher than the air pressureprevailing in the treatment vessel of the water-carrying cleaningmachine, so that it has been possible to reduce the danger of the entryof moisture into the apparatus and to improve the expulsion of themetered detergent. The aforementioned apparatus has a movable protectiveflap for the detergent outlet opening. It has now been found in practicethat that protective flap, because of its rotary motion, entrains tracesof moisture to the outlet opening, which despite the constant outflow ofcompressed air still leads to clumping of detergent in the outletopening and in the metering receptacles and thus causes functionaldisruptions up to the point of inability of the apparatus to function.Moreover, the flap in motion and its seal entrains particles ofdetergent, which exert a pronounced scouring action and which damage theseal and the sealing face. The apparatus according to PublishedInternational Patent Application WO 93/18702 has a metering device witha plurality of metering receptacles; the outlet opening is disposed inthe upper region of the housing, so that the uppermost meteringreceptacle can be emptied. As a result, fine to superfine particles ofdetergent enter the lower portion of the chamber receiving the meteringdevice, which as has been found in practice leads to such pronouncedfriction at the metering device that disruptions in function up to thepoint of inability of the apparatus to function can occur. In order toovercome the friction, a very high torque must be imposed for drivingthe metering device. A further disadvantage has proved in practice to bethat the discharging of a total metered single quantity of detergentnecessitates a pronounced air flow, or in other words a high pressure ofthe compressed air acting upon the apparatus. Moreover, the complexityand the number of parts, especially large-volume parts that are inmotion, is a disadvantage in the apparatus of Published InternationalPatent Application WO 93/18702, because that makes for high costs of theapparatus in terms of manufacture and installation, and as already notedabove, a high torque is needed to drive the large parts in motion.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide an apparatus forrepeated, automatic metering of precisely metered quantities of apowdered detergent into water-carrying cleaning machines, in particularhousehold dishwashers and household washing machines, which overcomesthe hereinafore-mentioned disadvantages of the heretofore-known methodsand devices of this general type in a simple way and creates a methodfor advantageous operation of the apparatus of the invention.

With the foregoing and other objects in view there is provided, inaccordance with the invention, an apparatus for repeated, automaticmetering of precisely metered quantities of a powdered detergent intowater-carrying cleaning machines, in particular household dishwashersand household washing machines, comprising a detergent holder with anoutlet opening above a metering and dispensing device having at leastone loading and one dispensing position, being equipped with a movablemetering device having at least one metering receptacle for receiving asingle metered quantity of the powdered detergent, the detergent beingfed into a treatment vessel of the water-carrying cleaning machine, aninterior of the detergent holder and a guide of the metering anddispensing device being acted upon continuously by a stream ofcompressed air, and the stream of compressed air in the dispensingposition also acting upon the interior of the metering receptacle, themetering device having only one metering receptacle for receiving asingle metered quantity of the powdered detergent; the metering anddispensing device having two chambers communicating with one another,including a first chamber communicating with the detergent holder beingdisposed below the outlet opening of the detergent holder, and thedetergent fed into the first chamber being fed gradually, during themotion of the metering device, into a second chamber, having an openingtoward the treatment vessel; the treatment vessel-side opening of thesecond chamber being closed, in the loading position, by a lid connectedto the metering device, the lid, in the dispensing position, uncoveringa discharge opening, from which the metered detergent is fed graduallyto the treatment vessel; and sealing elements surrounding the treatmentvessel-side opening of the second chamber and cooperating with the lidbeing disposed on a housing of the metering and dispensing device.

Since the metering device has only one metering receptacle, only a smallpart has to be put into motion, and so the drive of the apparatus of theinvention can be operated with substantially lower torque than in theprior art described above. Moreover, the apparatus of the invention thusbecomes substantially less complex than in the prior art described, andis thus more economical to manufacture and install. Since the meteringreceptacle of the metering device evacuates the detergent into a secondchamber which communicates with the first chamber, the deposit ofdetergent particles, which might rub against or scour the meteringdevice, is effectively avoided in a simple way, which once again enablesa substantial reduction in the required driving torque and effectivelyprevents problems in the function of the apparatus of the invention.Since the lid is connected to the metering device and thus is movedalong with it, a further reduction in complexity of the apparatus of theinvention is attained. As a result of the gradual discharge of detergentto the metering device, from there to the second chamber, and from thereinto the treatment vessel of the water-carrying cleaning machine, astill further reduction in the requisite driving torque for theapparatus of the invention is attained. It is also extraordinarilyadvantageous that particularly because of the gradual discharge of theaccurately metered quantity of detergent, the air flow used for thedischarge needs to be only substantially less strong in the apparatusaccording to the invention; that is, the compressed air flowing withinthe apparatus of the invention requires only a substantially lowerpressure, and so compared with the above-described prior art, asubstantially smaller compressed air generator, such as a pump used inaquariums, can be used and nevertheless an invasion of moisture into theapparatus of the invention is effectively prevented, and the detergentis reliably expelled from the apparatus of the invention. Due to thedisposition of sealing elements between the lid that moves with themetering device and the housing of the apparatus of the invention thatsurrounds the treatment-side opening of the chamber, seals on movingparts, which could be damaged by scouring by entrained detergentparticles, are avoided in a simple way. Moreover, an invasion ofmoisture into the apparatus according to the invention is effectivelyprevented with the sealing elements.

In accordance with another feature of the invention, the lid is actedupon by streams of a cleaning fluid which are generated in the treatmentvessel. Thus, entrained detergent particles which might stick to the lidare floated away, so that damage to the seals or the sealing face isavoided even better, and self-cleaning of the apparatus of the inventionis attained.

In accordance with a further feature of the invention, the movablemetering device is constructed essentially cylindrically and is disposedin the first chamber. With this provision, a further reduction in sizeof the only part in motion of the apparatus of the invention isattained, which in turn serves to lower the driving torque and thecomplexity of the apparatus of the invention.

In accordance with an added feature of the invention, the meteringdevice is rotatably supported in the housing of the metering anddispensing device and is disposed at a distance from the end of theoutlet opening, of the detergent holder associated with the firstchamber. By the definition of a simple rotary motion of the meteringdevice, a further reduction in the complexity in the apparatus of theinvention is attained. By disposing the metering device at a distancefrom the outlet opening of the detergent holder, additional frictionbetween the metering device and the detergent holder is avoided. Anydetergent which might settle out in very slight quantities reaches thesecond chamber and is expelled in the dispensing position of themetering and dispensing device.

In accordance with an additional feature of the invention, the meteringdevice is rotatably supported by a coupling bolt in the housing of themetering and dispensing device, so that in a simple way, the possibilityof coupling to a drive is combined with the necessity of the bearing.

In accordance with yet another feature of the invention, the dischargeof the accurately metered quantity of detergent from the apparatusaccording to the invention is made even easier, by providing that thesecond chamber is disposed substantially below the first chamber and hasa lower surface that drops downward toward the treatment vessel-sideopening.

In accordance with yet a further feature of the invention, the volume ofthe second chamber is smaller than the volume of the meteringreceptacle.

In accordance with yet an added feature of the invention, asimplification in the manufacture of the apparatus of the invention isattained in a simple way, by providing that both chambers have treatmentvessel-side openings, which are closed by the lid in the loadingposition of the apparatus according to the invention, and that sealingelements that surround the treatment vessel-side openings of bothchambers and which cooperate with the lid are disposed on a housing ofthe metering and dispensing device. Since the sealing elements encompassboth openings, the expense of separate sealing elements is avoided.

In accordance with yet an additional feature of the invention, simplemanufacture and therefore a reduction in cost for the apparatus of theinvention is attained, by providing that the lid is constructed as adisklike, substantially circular element.

In accordance with again another feature of the invention, the lid isformed onto the metering device, which makes the manufacture andinstallation of the apparatus of the invention even easier and morefavorable.

In accordance with again a further feature of the invention, in the lid,the discharge opening is disposed in the form of an aperture, havingside walls which are beveled or frustoconical and constructed with asharp-edged profile. The simple manufacture of an aperture means thatmanufacture and installation of the apparatus of the invention becomeeven easier and more favorable. The special shape of the aperture inaccordance with the further preferred embodiment of the inventionimproves the discharge of detergent from--the apparatus of theinvention. The sharp-edged periphery of the aperture with thesharp-edged profile provides a simple way of preventing entrainment ofdetergent particles.

In accordance with again an added feature of the invention, thedischarge opening leads ahead of the metering receptacle, in thedirection of motion of the metering device, in such a way that in themotion toward the metering position of the metering and dispensingdevice, the discharge opening at least partially uncovers the treatmentvessel-side opening of the second chamber even before the gradualfeeding of the detergent from the metering receptacle to the secondchamber begins. It is thus assured that even the first detergentparticles that are transferred from the metering receptacle canimmediately be expelled from the apparatus of the invention, so that thepressure of the air flow can be kept low. By this provision it is alsoattained that already quite early after the uncovering of the dischargeopening, approximately after half the length of the entire period oftime within which the discharge opening is in communication with thesecond chamber, the entire metered quantity of detergent is expelled, sothat it can be assured that even the slightest residues of detergentwill be blown out of the second chamber by the airflow.

In accordance with again an additional feature of the invention, thedischarging of the accurately metered quantity of detergent from theapparatus of the invention is made even easier by providing that a loweredge of the discharge opening, in the metering position of the meteringand dispensing device, is located somewhat lower than a lowermost edgeof the treatment vessel-side opening of the second chamber. As a result,the expelled detergent does not come into contact with the possibly dampside walls of the discharge-opening, so that adhesion and clumping ofthe detergent in the discharge opening is effectively prevented.

In accordance with still another feature of the invention, the lid ispermanently connected to a bearing bolt of the metering device, whichmeans that production and installation of the apparatus of the inventionbecome even easier and more favorable.

In accordance with still a further feature of the invention, the lid iseccentrically disposed on the bearing bolt in such a way that in themotion of the metering device toward the metering position of themetering and dispensing device, the uncovering of the discharge opening,or in other words the uncovering of the treatment vessel-side opening ofthe second chamber, begins even before the gradual feeding of thedetergent from the metering device begins. With this advantageousfeature of the invention, the making of an aperture for the dischargeopenings can be avoided in a simple way, which once again makesproduction and installation of the apparatus of the invention easier andmore favorable.

In accordance with still an added feature of the invention, anespecially effective prevention of the entrainment of detergentparticles and traces of moisture by the lid in motion is achieved byproviding that the sealing elements include at least one sharp-edgedsealing edge that protrudes toward the lid. Simple manufacture andtherefore a cost reduction for the apparatus of the invention isattained, in an advantageous feature of the invention, in that thesealing edges are formed on in the peripheral regions of the treatmentvessel--side openings of the two chambers.

In accordance with still an additional feature of the invention, afurther improvement in the effective prevention of the entrainment ofdetergent particles and traces of moisture by the lid in motion isattained by providing that the sealing elements include at least oneseal.

In accordance with another feature of the invention, a furtherimprovement in the effective prevention of the entrainment of detergentparticles and traces of moisture by the lid in motion is attained byproviding that the sealing elements include at least two concentricallydisposed sealing edges and between them at least two concentricallydisposed seals.

In accordance with a further feature of the invention, a furtherimprovement in the action of the sealing elements is attained byproviding that the metering device is pressed in the direction of thetreatment vessel-side openings by an elastic element, preferably aspring, acting between a counterholder secured to the housing of themetering and dispensing device, and the metering device, since by thismeans the lid secure to the metering device is pressed against thesealing elements.

In accordance with an added feature of the invention, simple manufactureand installation of the apparatus of the invention result by providingthat the counterholder is constructed as a bail, having at least one legthat is secured to the housing of the metering and dispensing device.

In accordance with an additional feature of the invention, an equallysimple production and installation of the apparatus of the invention isobtained by providing that the counterholder is constructed as adischarge vessel, which is secured to the housing of the metering anddispensing device and extends to the top and bottom beyond the lid, andinto which vessel the metered quantity of detergent is fed, wherein thedischarge vessel, below the lid, is closed through the use of a screenand above the lid has water inlet openings. With this advantageousfeature of the invention, a further gradual delivery of the detergent tothe cleaning machine is also attained, because the detergent drops ontoa screen and is loosened and carried away from below by the streams ofliquid generated in the cleaning machine and from above by the liquidentering through the water inlet openings.

In accordance with again another feature of the invention, a furtherimprovement in function of the apparatus of the invention is attained byproviding that the metering device is rotatably supported in thecounterholder by the bearing bolt opposite the coupling bolt. A meteringdevice that is supported at two points requires even less drivingtorque. In accordance with again a further feature of the invention,cleaning and maintenance of the apparatus according to the invention arefacilitated by providing a drive that can be disconnected from thecoupling bolt and the housing of the metering and dispensing devicewhich engages the coupling bolt.

In accordance with again an added feature of the invention, the cleaningand maintenance of the apparatus according to the invention arefacilitated by providing that the apparatus is disconnectably secured inthe water-carrying cleaning machine.

With the objects of the invention in view, there is also provided amethod for dispensing accurately metered quantities of a powdereddetergent into water-carrying cleaning machines, in particular householddishwashers and household washing machines, through the use of anapparatus for repeated, automatic metering of accurately meteredquantities of a powdered detergent into water-carrying cleaningmachines, in particular household dishwashers and household washingmachines, which comprises moving a metering device by a continuous, slowdrive in such a way that a metering receptacle moves slowly beneath anoutlet opening of a detergent holder, and an accurately metered quantityof detergent can flow gradually by its own weight out of the detergentholder into the metering receptacle; upon continuous slow motion of themetering device, the beginning of a slow uncovering of a dischargeopening takes place, leading somewhat in advance of the position of themetering receptacle; upon continuous slow motion of the metering device,a gradual pouring out of the metered quantity of detergent from themetering receptacle into a second chamber takes place; and theaccurately metered quantity of detergent transferred to the secondchamber is gradually fed through the discharge opening, as a result of adownward-sloping lower surface of the second chamber and of an airflowprevailing in the second chamber, into the interior of a treatmentvessel of the water-carrying cleaning machine.

Through the use of the gradual delivery of detergent to the meteringdevice, from the metering device to the second chamber, and from thereinto the cleaning machine and through the slow motion of the meteringdevice and of the lid, it has become possible, with the method of theinvention, for the above-described apparatus of the invention, whoseadvantages listed above also pertain to the method of the invention, tobe realized while preserving these advantages.

Other features which are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin an apparatus and a method for repeated, automatic metering ofprecisely metered quantities of a powdered detergent into water-carryingcleaning machines, in particular household dishwashers and householdwashing machines, it is nevertheless not intended to be limited to thedetails shown, since various modifications and structural changes may bemade therein without departing from the spirit of the invention andwithin the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic, front-elevational view of a preferredembodiment of the apparatus of the invention;

FIG. 2 is a longitudinal-sectional view of the apparatus of theinvention in accordance with the preferred embodiment, which is takenalong a line II--II of FIG. 1, in the direction of the arrows;

FIG. 3 is a longitudinal-sectional view of the apparatus of theinvention in accordance with the preferred embodiment, which is takenalong a line III--III of FIG. 2, in the direction of the arrows, showingthe apparatus of the invention in accordance with the preferredembodiment at the beginning of its loading position;

FIG. 4 is a view similar to FIG. 3 showing the apparatus of theinvention in accordance with the preferred embodiment during its loadingposition;

FIG. 5 is a view similar to FIG. 3 showing the apparatus of theinvention in accordance with the preferred embodiment at the beginningof its dispensing position;

FIG. 6 is a view similar to FIG. 3 showing the apparatus of theinvention in accordance with the preferred embodiment at the end of itsdispensing position;

FIG. 7 is an exploded perspective view of the apparatus of the inventionin accordance with the preferred embodiment;

FIG. 8 is a fragmentary, enlarged view of a portion VIII of FIG. 2;

FIG. 9 is a view similar to FIG. 8, in accordance with a particularfeature of a metering device and sealing elements of the preferredembodiment of the apparatus according to the invention;

FIG. 10 is a fragmentary, longitudinal-sectional view of a furtherembodiment of an apparatus according to the invention;

FIG. 11 is a longitudinal-sectional view of a further embodiment of theapparatus of the invention, which is taken along a line XI--XI of FIG.10, in the direction of the arrows;

FIG. 12 is a longitudinal-sectional view showing a location of a lid atthe beginning of the loading position of the apparatus of the inventionin accordance with the further embodiment;

FIG. 13 is a view similar to FIG. 12 showing the location of the lid inthe loading position of the apparatus of the invention in accordancewith the further embodiment;

FIG. 14 is a view similar to FIG. 12 showing the location of the lid atthe beginning of the dispensing position of the apparatus of theinvention in accordance with the further embodiment;

FIG. 15 is a view similar to FIG. 12 showing the location of a lid inthe dispensing position of the apparatus of the invention in accordancewith the preferred embodiment;

FIG. 16 is a fragmentary, longitudinal-sectional view of the apparatusof the invention in accordance with the preferred embodiment having aparticular feature of a counterholder; and

FIG. 17 is an enlarged fragmentary view of a portion XVII of FIG. 10,with a particular embodiment of sealing elements of the apparatus of theinvention in accordance with the preferred embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now in detail to the figures of the drawing which show a firstembodiment in FIGS. 1-9 and a second embodiment in FIGS. 10-17, it isseen that in the drawings, two embodiments of an apparatus 1, 1'according to the invention are illustrated by using the same referencenumerals for identical parts. In the exemplary embodiments shown, theapparatus 1, 1' according to the invention is intended for use in ahousehold dishwasher, not described in further detail. The apparatus 1,1' according to the invention for repeated, automatic metering ofprecisely metered quantities of a powdered detergent into water-carryingcleaning machines, in particular household dishwashers and householdwashing machines, substantially includes a detergent holder 10, 10' anda metering and dispensing device 20, 20', with the detergent holder 10,10' disposed above the metering and dispensing device 20, 20'.

An interior 12, 12' of the detergent holder 10, 10' is closed with a cap11 in water-tight fashion through the use of sealing elements notdescribed in further detail, and it extends in funnellike fashion in itslower region, terminating in an outlet opening 13, 13'. The apparatus 1,1' of the invention in accordance with the exemplary embodiments shownpasses, as will be described in further detail below, through a loadingposition (FIGS. 2, 3, 4, 11, 12 and 13), in which the single meteredquantity of detergent is transferred from the detergent holder 10, 10'to the metering and dispensing device (20, 20'), and a dispensingposition (FIGS. 5, 6, 14 and 15), in which the single metered quantityof detergent is discharged into a treatment vessel 2, 2' of thehousehold dishwasher.

According to the invention, the metering and dispensing device 20, 20'has two chambers communicating with one another, that is, a firstchamber 22, 22' and a second chamber 23, 23'; the first chamber 22, 22',communicating with the detergent holder 10, 10', is disposed below theoutlet opening 13, 13' of the detergent holder 10, 10', and the secondchamber 23, 23' is disposed below the first chamber 22, 22'. In a mannerto be described in detail hereinafter, the detergent delivered to thefirst chamber 22, 22' is delivered gradually into the second chamber2-3, 23' during the motion of the metering and dispensing device 20,20'. Both chambers 22, 22', 23, 23' have treatment vessel-side openings24, 24', 25, 25', and the second chamber 23, 23' has a downward-slopinglower surface 26, 26' in the direction of the treatment vessel-sideopenings 25, 25'.

The metering and dispensing device 20, 20' has a rotating part 30, 30',which is equipped with a movable metering device 31, 31a, 31', whichaccording to the invention has merely a single metering receptacle 32,32' for receiving a single metered quantity of powdered detergent. Themetering device 31, 31a, 31' is constructed substantially cylindricallyand is disposed in the first chamber 22, 22'.

The metering device 31, 31a, 31' is rotatably supported by a couplingbolt 33, 33' in a housing 21, 21' of the metering and dispensing device20, 20' and is disposed at a distance a, a' from the end, associatedwith the first chamber 22, 22', of the outlet opening 13, 13' of thedetergent holder 10, 10'.

The volume of the second chamber 23, 23' is smaller than the volume ofthe metering receptacle 32, 32'.

The exemplary embodiments shown, of the apparatus 1, 1' of the inventionshare the fact that the interior 12, 12' of the detergent holder 10, 10'and a guide of the metering and dispensing device 20, 20' are acted uponcontinuously by a flow of compressed air; in the dispensing position,the flow of compressed air also acts upon the interior of the meteringreceptacle 32, 32'. The compressed air is generated in a compressed airgenerator that is not described in further detail herein and is fedthrough an air conduit 3, 3' into the metering and dispensing device 20,20', where it terminates in the second chamber 23, 23'.

Another feature shared by the exemplary embodiments shown of theapparatus 1, 1' of the invention is that the treatment vessel-sideopenings 24, 24', 25, 25' of the two chambers 22, 22', 23, 23' areclosed in the loading position by a lid 35, 35', which is connected tothe metering device 31, 31a, 31' and in the dispensing position uncoversa discharge opening 36, 36', from which the metered detergent isgradually delivered to the treatment vessel 2, 2'. The lid, 35, 35' isconstructed as a disklike, substantially circular element. As will bedescribed in further detail for the various exemplary embodiments, thelid 35, 35' is acted upon by streams of a cleaning fluid that aregenerated in the treatment vessel 2, 2'.

In the exemplary embodiments shown of the apparatus 1, 1 of theinvention, sealing elements 40, 40a, 40', 40'a that surround thetreatment vessel-side openings 24, 24', 25, 25' of both chambers 22,22', 23, 23' and which cooperate with the lid 35, 35' are disposed on ahousing 21, 21' of the metering and dispensing device 20, 20'. Thesesealing elements 40, 40a, 40', 40'a include at least one sharp-edgedsealing edge 41, 41', 42 that protrudes toward the lid 35, 35'. Thesesealing edges 41, 41', 42 are formed on in the peripheral regions of thetreatment vessel-side openings 24, 24', 25, 25' of the two chambers 22,22', 23, 23' onto the housing 21, 21' of the metering and dispensingdevice 20, 20'.

The metering device 31, 31a, 31' is pressed in the direction of thetreatment vessel-side openings 24, 24', 25, 25' by an elastic element49, 49', preferably a spring, acting between a counterholder 45, 45',45" secured to the housing 21, 21' of the metering and dispensing device20, 20', and the metering device 31, 31a, 31'.

The apparatus 1, 1' is driven by a drive 50, 50', which engages thecoupling bolt 33, 33' and can be disconnected from the coupling bolt 33,33' and from the housing 21, 21' of the metering and dispensing device20, 20'.

The entire apparatus 1, 1' of the invention is, as explained for each ofthe various embodiments, disconnectably secured in the householddishwasher.

Explanation of the function, which is the same for both exemplaryembodiments shown, of the apparatus 1, 1' according to the invention, orin other words of the method of the invention for operating theapparatus 1, 1' of the invention:

The metering and dispensing operation can be set into motion in thehousehold dishwasher by a program control, not described in furtherdetail, at predetermined times of the dishwashing program. Then themetering device 31, 31a, 31' is moved through the use of the continuous,slow drive 50, 50', in such a way that the metering receptacle 32, 32'rotates slowly below the outlet opening of the detergent holder 10, 10'(see FIGS. 2, 3, 4, 11, 12 and 13). An accurately metered quantity ofdetergent can then flow gradually out of the detergent holder 10, 10'into the metering receptacle 32, 32' by its own weight. Duringcontinuous slow motion of the metering device 31, 31a, 31', leadingsomewhat in advance of the position of the metering receptacle 32, 32',the beginning of a slow uncovering of the discharge opening 36, 36' thenensues (see FIGS. 5 and 14). Now, because of the continuous slow motionof the metering device 31, 31a, 31', a gradual pulling out of themetered quantity of detergent takes place from the metering receptacle32, 32' into the second chamber 23, 23' (see FIGS. 5, 6, 14 and 15); atthe same time, the accurately metered quantity of detergent transferredto the second chamber 23, 23' is gradually fed into the interior of thetreatment vessel 2, 2' of the household dishwasher through the dischargeopening 36, 36', as a result of the down-sloping lower edge of thesecond chamber 23, 23' and the air flow prevailing in the second chamber23, 23'. Due to the slow, continuous drive of the metering device 31,31a, 31', the discharge opening 36, 36' remains open for a rather longtime, so that already quite soon after the uncovering of the dischargeopening 36, 36', and empirically after about half the length of theentire time period within which the discharge opening 36, 36' is incommunication with the second chamber 23, 23', the entire meteredquantity of detergent is expelled so that it is possible to assure thatthrough the use of the air flow even the slightest residues of detergentwill be blown out of the second chamber 23, 23'. After the closure ofthe treatment vessel-side opening 25, 25' of the second chamber 23, 23',the metering device 31, 31a, 31' is put by the drive 50, 50' into aposition of repose, which is located just before the loading position ofthe apparatus 1, 1' of the invention, and the metering and dispensingoperation with the apparatus 1, 1' of the invention is at an end. It isnaturally possible at any time, for example on a request for dispensinga plurality of accurately metered quantities of detergent, to cause theabove-described operation to proceed multiple times in a single cleaningcycle.

As is known per se, to perform the method of the invention it is assumedthat at least during the dispensing of the accurately metered quantityof detergent into the treatment vessel 2, 2' of the water-carryingcleaning machine, the devices in the machine for producing streams of acleaning fluid, and/or for recirculating a cleaning fluid, in thetreatment vessel 2, 2', for example in the spray arms present in thehousehold dishwasher, are not operated or are not supplied with cleaningfluid.

The special features of the preferred embodiment of the invention (FIGS.1-9) will now be described.

The drive 50 of the metering and dispensing device 20 of the preferredembodiment of the invention is constructed as an actuator 51 with a gear52. It is disposed in the non-illustrated door of the householddishwasher and protrudes through an inner door 7, with the interpositionof a suitable seal 54, by a transfer shaft 53 into the coupling bolt 33of the metering device 31. The detergent holder 10 is disconnectablymounted on the housing 21 of the metering and dispensing device 20through the use of a collar 14, which is inserted into a receiving bore15 in the housing 21. The transition from the receiving bore 15 to thefirst chamber 22 of the metering and dispensing device 20 is formed by afrustoconical conduit 16. The above-described fastening configurationmakes it clear that the apparatus 1 of the invention in the preferredembodiment can be removed entirely, except for the drive 50, in a simpleway from the household dishwasher and removed for maintenance purposes,or can be disconnected from the -metering and dispensing device 20 forfilling of the detergent holder 10 and then removed from the householddishwasher. The fastening of the removable apparatus 1 according to theinvention in the preferred embodiment can be constructed in detail asdescribed in Italian Patent Application 67125-A/90. The drive 50 mayalternatively be constructed as an electric motor with a gear, forinstance.

The non-illustrated compressed air generator is also disposed in thedoor of the household dishwasher, in order to save space.

In the preferred embodiment of the invention, the lid 35 is formed ontothe metering device 31, in which the discharge opening 36 is disposed inthe form of an aperture, having side walls 37 which, in the exemplaryembodiment shown, are beveled and constructed with a sharp-edged profile38 (see FIG. 8). A lower edge 39 of the discharge opening 36 is locatedsomewhat lower, in the dispensing position of the metering anddispensing device 20, than a lowermost edge 29 of the treatmentvessel-side opening 25 of the second chamber 23 (see FIG. 5). As canclearly be seen in FIG. 8, the lid 35 with the discharge opening 36, inthe position of repose, protrudes beyond the housing 21 of the meteringand dispensing device 20 and is in the open. The lid 35, on both itsinner and outer surface, and the discharge opening 36 can therefore beacted upon and thus cleaned by the streams of a cleaning fluid generatedin the treatment vessel 2, so that self-cleaning of the apparatus 1according to the invention in the preferred embodiment is attained.

The discharge opening may also be constructed frustoconically.

In order to carry out the transfer of the quantity of detergent placedin the metering receptacle 32 by the above-described method of theinvention, the discharge opening 36 is disposed, leading ahead of themetering receptacle 32 in the direction of motion of the metering device31, in such a way that in the motion toward the dispensing position ofthe metering and dispensing device 20, the discharge opening 36 reachesthe treatment vessel-side opening 25 of the second chamber 23 evenbefore the beginning of the gradual delivery of detergent from themetering receptacle 32 to the second chamber 23, or in other wordsbefore the metering device 31 has rotated in such a way that detergentcan trickle out of the metering receptacle 32 into the second chamber23.

In the apparatus 1 of the invention in accordance with the preferredembodiment of the invention, the sealing elements 40 include two sealingedges 41, 42, disposed concentrically around the treatment vessel-sideopenings 24, 25 of the two chambers 22, 23, and two concentricallydisposed seals 43, 44 between these sealing edges, as can best be seenfrom FIG. 8. The sealing edges 41, 42 of the apparatus according to theinvention in the preferred embodiment are constructed as lamination-likescrapers. The inner sealing edge 42 provides sealing against thedetergent from the second chamber 23 and thus also protects the innerseal 44 against scouring residues of detergent particles. The outersealing edge 41 provides sealing against dust entering from outside andthus protects the outer seal 43 against scouring residues. The seals 43,44 form a dual protection against the entry of moisture into theapparatus 1 according to the invention.

The counterholder 45 is constructed as a bail, having two legs 46, 47which are secured in the manner of a bayonet mount in receiving slits 48on the housing 21 of the metering and dispensing device 20. Theinstalled position of the bail 43 is indicated by dot-dashed lines inFIG. 2. FIG. 9 shows a special feature of the metering device 31a of theapparatus 1 of the invention in the preferred embodiment; the meteringdevice 31a is equipped, at the points that come into contact with thehousing 21, with channels 60 which on one hand reduce the frictionbetween the housing 21 and the metering device 31a and on the other handcarry detergent particles that invade the second chamber 23 onto thedown- sloping lower surface 26.

FIG. 9 also shows a particular embodiment of sealing elements 40a of theapparatus 1 of the invention in the preferred embodiment; a seal 65 hasan inner part 66 and an outer part 67, and the inner part 66 has greaterelasticity than the outer part 67. The seal 65 is essentially in theform of a double trapezoid. Due to this shape and because of themore-elastic inner part 66, the seal 65 can act as a spring and cancompensate for possible abrasion of the outer part 67, which rests onthe inner surface of the lid 35, or for major deformation. The frictionbetween the lid 35 and the seal 65 is thus reduced.

The method of the invention for dispensing accurately metered quantitiesof a powdered detergent into the household dishwasher through the use ofthe apparatus 1 according to the invention in the preferred embodimentof the invention will now be described in conjunction with FIGS. 3-6.

FIG. 3 shows how the metering device 31 is moved, through the use of thecontinuous, slow drive 50, that the metering receptacle 32 moves slowlyto beneath the outlet opening 13 of the detergent holder 10, and thegradual transfer of detergent from the detergent holder 10 to themetering receptacle 32 has already begun.

In FIG. 4, the entire metering receptacle has now reached the locationbelow the outlet opening 13 of the detergent holder 10, and anaccurately metered quantity of detergent can flow by its own weight outof the detergent holder 10 gradually into the metering receptacle 32.

In FIG. 5, with continuous slow motion of the metering device 31 leadingsomewhat ahead of the position of the metering receptacle 32, thedischarge opening 36, which is shown in solid lines in FIGS. 3-6 forbetter visibility, has reached the treatment vessel-side opening 25 ofthe second chamber 23, and the gradual pouring out of the meteredquantity of detergent from the metering receptacle 32 into the secondchamber 23 has begun; the accurately metered quantity of detergenttransferred to the second chamber 23 is gradually delivered through thedischarge opening 36 into the interior of the treatment vessel 2 of thehousehold dishwasher, because of the down-sloping lower surface 26 ofthe second chamber 23 and the air flow prevailing in the second chamber23. Due to the disposition somewhat in advance of the meteringreceptacle 32 and because of the slow continuous drive of the meteringdevice 31, the discharge opening 36 remains open rather long, so thatalready quite soon after the uncovering of the discharge opening 36, andempirically after about half the length of the entire period of timeduring which the discharge opening 36 is in communication with thesecond chamber 23, the entire metered quantity of detergent is expelled,so that it can be assured that through the use of the air flow even themost minimal residues of detergent can be blown out of the secondchamber 23.

In FIG. 6, the dispensing operation to the household dishwasher isconcluded, and the discharge opening 36 has already almost left thetreatment vessel-side opening 25 of the second chamber 23 behind. Themetering device 31 is rotated by the continuous slow drive 50 into aposition of repose just before the loading position of FIG. 3, and thusthe treatment vessel-side opening 25 of the second chamber 23 is closedagain, and a new metering and dispensing operation can begin, forinstance controlled by a program control of the household dishwasherthat is not described in further detail herein. It is naturally possibleat any time, for instance on a request for the dispensing of a pluralityof accurately metered quantities of detergent, to cause theabove-described operation to be performed multiple times within onecleaning cycle.

The special features of the further embodiment of the invention (FIGS.10-17) will now be described.

In contrast to the above-described configuration of the apparatus 1 ofthe invention in the preferred embodiment in the household dishwasher,the apparatus 1' of the invention in accordance with the furtherembodiment is disposed substantially in a non-illustrated door of thehousehold dish-washer and is secured, through the use of a threaded ring4', which is screwed to a threaded collar 5' of the housing 21' of themetering and dispensing device 20', to an aperture of an inner door 7'with the interposition of a suitable seal 6', in such a way thatessentially only the treatment vessel-side opening 24', 25', the lid35', and the counterholder 45', 45" protrude into the treatment chamber2' of the household dishwasher.

In addition to the bearing in accordance with the above-describedpreferred embodiment of the invention, in the further embodiment of theinvention the metering device 31' is rotatably supported in thecounterholder 45', 45" by a bearing bolt 34' opposite the coupling bolt33'.

As shown in FIG. 10, the counterholder 45' is constructed as a bail onone side, having a leg 46' which is secured to the housing 21' of themetering and dispensing device 20' in the manner of a bayonet mount.

The lid 35' is permanently connected to the bearing bolt 34' of themetering device 31' and is eccentrically disposed in such a way thatupon the motion of the metering device 31' toward the dispensingposition of the metering and dispensing device 20', the uncovering ofthe discharge opening 36', or in other words the uncovering of thetreatment vessel-side opening 25' of the second chamber 23', begins evenbefore the beginning of the gradual delivery of detergent from themetering receptacle 32', since as a result of the eccentric dispositionof the circular lid 35', a lower edge 39' of the lid 35' lifts up overthe lowermost edge 2-7' of the treatment vessel-side opening 25' of thesecond chamber 23'. Since the bail-shaped counterholder 45' onlyslightly covers the lid 35', the lid 35' can be acted upon and thereforecleaned by the streams of a cleaning fluid generated in the treatmentvessel 2', so that self-cleaning of the apparatus 1' according to theinvention in the further embodiment is attained.

As an alternative to the drive 50 through the use of an actuator 51 andgear 52 used in the first-described preferred embodiment of theinvention above, the drive 50' of the metering and dispensing device 20'of the further embodiment of the-invention is formed by anon-illustrated electric motor with a gear of which only a gear wheel52' is shown, which protrudes with a transmission part 53' into thehousing 21' of the metering and dispensing device 20' with theinterposition of a suitable seal 54' and is disconnectably connected tothe coupling bolt 33' of the metering device 31'.

In FIG. 17, a particular embodiment of sealing elements 40'a of theapparatus 1' of the invention in the further embodiment is shown; thealternative use of a seal 43', a so-called quad ring, is shown inaddition to the sealing edge 41' or as a substitute for the sealing edge41'.

In FIG. 16, a particular embodiment of the counterholder 45" inaccordance with the further embodiment of the invention is shown; thecounterholder 45" is constructed as a discharge container 55", which issecured to the housing 21 of the metering and dispensing device 20' andextends outward beyond the lid 35' at the top and bottom. The meteredquantity of detergent is delivered to the discharge container 55", andthe discharge container 55" is closed through the use of a screen 56"below the lid 35' and has water inlet openings 57" above the lid 35'.The detergent expelled by the metering and dispensing device 20' intothe discharge container 55" drops onto the screen 56" and is detachedand carried away from below by the streams of liquid generated in thecleaning machine and from above by the liquid entering through the waterinlet openings 57". The liquid entering through the water inlet openings57" is naturally also embodied by streams of a cleaning fluid generatedin the treatment vessel 2'. Since this cleaning fluid in the dischargecontainer 55" can also reach the lid 35 unhindered, the lid 35 is actedupon by the cleaning fluid and cleaned, so that in this particularfeature of the counterholder 45" of the apparatus 1' of the invention inaccordance with the further embodiment as well, a self-cleaning effectis attained.

The method of the invention for dispensing accurately metered quantitiesof a powdered detergent into the household dishwasher through the use ofthe apparatus 1' of the invention in accordance with the furtherembodiment of the invention is described in conjunction with FIGS. 12,13, 14 and 15, which show it schematically. For better illustration, thehousing 21' of the metering and dispensing device 20', the detergentholder 10', and the metering device 31' are shown shaded in FIGS. 12,13, 14 and 15. The lid 35' is shown as a solid line.

The metering device 31' is moved through the use of the continuous, slowdrive 50', in such a way that the metering receptacle 32' rotates slowlyto underneath the outlet opening 13' of the detergent holder 10' (seeFIG. 12), and an accurately metered quantity of detergent can flowgradually by its own weight out of the detergent holder 10' into themetering receptacle 32'. The lid 35 covers the treatment vessel-sideopenings 24', 25' of the two chambers 22', 23'. In the position shown inFIG. 13, the metering receptacle 32' has fully reached the positiondirectly below the outlet opening 13'. There, the lid 35' still coversthe treatment vessel-side openings 24', 25' of the two chambers 22',23'.

During continuous slow motion of the metering device 31', somewhat inadvance of the position of the metering receptacle 32', the beginning ofa slow uncovering of the discharge opening 36' now ensues, since thelower edge 39' of the lid 35' lifts up over the lowermost edge 27' ofthe treatment vessel-side opening 25' of the second chamber 23'. This isthe beginning of the uncovering of the discharge opening 36', as shownin FIG. 14; the transfer of the metered quantity of detergent from themetering receptacle 32' to the second chamber 23' has not yet begun,because of the disposition of the lid 35' leading ahead of the positionof the metering receptacle 32'. During continuous slow motion of themetering device 31', a gradual pouring out of the metered quantity ofdetergent from the metering receptacle 32' into the second chamber 23'now ensues, and at the same time, the quantity of detergent graduallytransferred to the second chamber 23' is gradually fed through thedischarge opening 36' into the interior of the treatment vessel 2' ofthe household dishwasher (see FIG. 10) or into the discharge container55" and from there into the treatment vessel 2' of the householddishwasher (see FIG. 16), because of the down-sloping lower surface 26'of the second chamber 23' and because of the air flow prevailing in thesecond chamber 23'. In FIG. 15, the discharge opening 36' isschematically shown; it is formed by the lifted-up edge 39' of the lid35' and by the exposed lowermost edge 27' of the treatment vessel-sideopening 25' of the second chamber 23'. In this further variant of theinvention as well, because of the slow continuous drive of the meteringdevice 31', the discharge opening 36' remains open rather long, so thatalready quite early after the uncovering of the discharge opening 36',empirically after about half the length of the entire period of timewithin which the discharge opening 36' is in communication with thesecond chamber 23', the entire metered quantity of detergent isexpelled, so that it can be assured that because of the air flow eventhe least residues of detergent are blown out of the second chamber 23'.Thus in the position of FIG. 15, in the apparatus 1' according to thefurther embodiment, the entire quantity of detergent has already beenexpelled.

After the conclusion of the operation of dispensing to the householddishwasher, the discharge opening 36' and with it the treatmentvessel-side opening 25' of the second chamber 23' are closed again, as aconsequence of the continuous slow movement of the metering device 31'and therefore of the lid 35'. The metering device 31' is rotated backinto a position of repose prior to the beginning of the loading positionof FIG. 12 by the continuous slow drive 50', and a new metering anddispensing operation can begin, for instance controlled by a programcontrol, not described in further detail, of the household dishwasher.It is naturally possible at any time, for example on a request--for thedispensing of a plurality of accurately metered quantities of detergent,to cause the above-described operation to proceed multiple times withinone cleaning cycle.

We claim:
 1. A method for dispensing accurately metered quantities of apowdered detergent into water-carrying cleaning machines, in particularhousehold dishwashers and household washing machines, with an apparatusfor repeated, automatic metering of accurately metered quantities of apowdered detergent into water-carrying cleaning machines, in particularhousehold dishwashers and household washing machines, whichcomprises:moving a metering device with a continuous, slow drive formoving a metering receptacle slowly beneath an outlet opening of adetergent holder, and permitting an accurately metered quantity ofdetergent to flow gradually by its own weight out of the detergentholder into the metering receptacle; continuously slowly moving themetering device for beginning a slow uncovering of a discharge opening,leading somewhat in advance of the position of the metering receptacle;continuously slowly moving the metering device for gradually pouring outthe metered quantity of detergent from the metering receptacle into achamber; and gradually feeding the accurately metered quantity ofdetergent transferred to the chamber through the discharge opening, as aresult of a downward-sloping lower surface of the chamber and of anairflow prevailing in the chamber, into the interior of a treatmentvessel of the water-carrying cleaning machine.